(1) Field of the Invention
This invention relates to dehydration of ethylene glycol in a reboiler and more particularly to enhanced dehydration by sparging the reboiled liquid while still in the reboiler, using dry gas as the sparging medium.
(2) Description of the Prior Art
Heretofore it has been known to introduce dry gas into a stream of partially dried glycol before heating it in the coil of a liquid tube reboiler, as disclosed in U.S. Pat. No. 2,428,643--Young (filed 1944).
In a preprint of a paper to be delivered by Steve Worley to a Gas Conditioning Conference sponsored by the Oklahoma Continuing Education Center at the University of Oklahoma it is stated that in the years 1950-51 B. S. and B. sold glycol reboilers with provision for introduction of natural gas into the reboiler. (Paper to be delivered April 1967).
In U.S. Pat. No. 3,105,748--Stahl (filed 1957), it is disclosed that dry gas can be introduced into a saddle packed superdrier to contact partially dried glycol from a reboiler.
In U.S. Pat. No. 3,233,390--Meyers (filed 1963), it is disclosed that dry gas can be introduced into a rear compartment of a glycol reboiler tank, the compartment being separated from the front or fire tube compartment by a weir. The gas is introduced into the bottom of the rear compartment by a spreader. Somewhat similarly, it is shown in U.S. Pat. No. 3,397,731--Gravis III et al. (filed 1966) that dry gas may be admitted to the bottom rear portion of a fire tube reboiler tank. The rear portion of the tank is separated from the front portion by a weir. The gas is admitted via sparger pipes extending beneath a plurality of baffles in the rear portion of the tank. The pipes run parallel to the pipe axis and fire tubes.
It is also known to introduce dry gas into the front section of a two section reboiler tank via a sparging pipe extending transversely of the tank just ahead of the weir that divides the front or fire tube section of the tank from the rear or storage section, and as will be described in more detail hereinafter, it is known to introduce dry gas into a section of a fire tube reboiler tank downstream from a weir separating the front or fire tube section from the remainder of the tank.